In a medium bowl, sift together the flour, baking powder, and salt; set aside. In a large bowl, cream the butter, shortening, and sugar until light and fluffy. Add the eggs and beat well. Add the flour mixture, alternating with the milk. Stir in the lemon extract.

Pour the batter into the prepared pan(s) and bake 1 hour for the loaves or 75 minutes for the cakes, or until a toothpick inserted into the middle comes out clean. Let the cake(s) cool in the pan(s).